Mr Mackay’s public speaking lesson was revealed in an answer to a Freedom of Information request, which also revealed that other Scottish Government ministers had received help with their presentation skills over the last few years.

A number had media training offered internally by the Scottish Government at no cost to the taxpayer. Others, like Mr Mackay, had public money spent on getting outside expertise.

In 2014/15, the then Education Secretary Angela Constance received £1,200 in media training from Pink Elephant Communications, a company founded by the TV presenter Bill McFarlan.

Others to receive the £1,200 session that year were Annabel Ewing, the then Youth and Women’s Employment Minister; the then Environment Minister Aileen MacLeod and the then Public Health Minister Maureen Watt.

In the same year, the current Transport Secretary and then Justice Secretary Michael Matheson had Pink Elephant Communications’ training at a cost of £1,440.

Scottish Conservative MSP Murdo Fraser said: “Derek Mackay may have felt he needed to spend public money to change his oratorical style from dalek to Demosthenes.

“But it’s not speaking lessons he needed – it’s a course in how not to fleece hardworking people in Scotland.

“This money from the taxpayer may have helped him deliver the budget more eloquently.

“But its contents remain deeply troubling and will have a real impact on family finances right across Scotland.”

A Scottish Government spokeswoman said: “In common with senior positions in other large organisations a range of training is made available to Ministers, including courses in media and public speaking skills.

“This training has an important role in supporting Ministers in their delivery of official government business. These courses are delivered in-house where possible.”